This invention relates to new aromatic compounds of the spartein series, to their use and to methods for their preparation. It also relates to medicaments which contain such compounds and to methods for the preparation of such medicaments. In one particular aspect the invention also relates to use of 17-substituted spartein derivatives, especially 17-benzyl and substituted benzyl spartein derivatives, with positive inotropic activity to treat ischemic and non-ischemic cardiac insufficiencies, and to the production of suitable pharmaceutical compositions for such treatments.
Spartein, an alkaloid which can be extracted from broom (Cvtisus scoparius), and its properties, which affect the heart and in particular influence the heart rhythm, have already been described in the technical literature.
An increase in effect with regard to extension of the refractory period can be achieved with sparteins substituted in position 17 by alkyl, i.e. compounds which have the following structure: ##STR2## Such compounds are described in DE-OS 23 60 475. Also, a dimeric spartein with antiarrhythmic effect, 17,17'-bisspartein, is described in published European patent application No. EP 46,565.
The compounds of the prior art display good properties in the treatment of heart rhythm complaints, but their activity patterns could still be improved upon.
The most widely known medicines with positive inotropic activity are heart glycosides (digitalis products and strophantin products). In addition to their positive inotropic activity which increases the beat volume they also lead indirectly to a decrease of the heart frequency through accommodation to the increased beat volume. The great disadvantage of the heart glycosides lies in their extraordinarily narrow therapeutic range, which is particularly limited by the heart arrhythmia inducing side effects of these preparations.
All other positive inotropically active medicines have the disadvantage that they do not decrease the heart frequency and in many cases even produce an increase in the heart frequency. This leads to an increased stress on the heart which is particularly undesirable in cases of insufficient heart pumping function.